Fountain pen



0. MITCHELL.

FOUNTAIN PEN.

APPLICATION FELED sEPTuzz, 1921.

Patented @et i atented et.. ld, lg',

To all Lv/0m timely concern tain lisation.y

Myinventionis `an improvement in fountainpens andjeonsists' in theprovision at therear of the fountainlor barrel of such apen, ofaineansvfor withdrawing air from at the 4forward end thefbarrel toa'compartinentatf-the upper `endv of the barrel, thus rarifying the air in:the barrelandvcausing` an inflow of ink of the barrel `by theouter ratmospheric pressure and later discharging the air from the uppercompartment through tothe pen endfof the barrel.

apipe. leading from the upper compartment This operation is'repeatedasoften as may be necessary to L emptyfthebarleljofrair land fill thebarrel terior parts as at-the end witlrink." Y "Injtherdrawingszf if yigureV l is a longitudinal sectional elevation 'of a fountain penembodying my imparts as at the end of' the' air-expelling stroke;

`Figure 2 is a'erossfsection on line 2 2 of Figurely"` Figure 1;;

Figure 4 is a partial e medcation; and.` i

' Figure "5 is "a3 partialy sectional elevation of the device of Figurel. showing the inof the outward Figure :13 isa cross-section on line3--3 of stroke of the suction cup.

`The mechanism of my improved pen is of the simplest. y The fountain lcarries at one end the feed bar 2 having ink feeding fissures 3 and apen point 4l, as is usual. The ink feed bar has, in addition to the' inkssures 3 another passage 5, which at its inner end is `central of thebarand fountain, that is, corresponds with the longitudinal d axis ofthe fountain and is connected with a pipe A extending axially of thefountain i to near the top or rearend of the same.

Slidably tting at the rear upper end of the fountain is a cup or chamberB, and

within this chamber and frictionally en-` gaging the same, is a disk Cwhich is mounted upon the pipe A and hasla slight capacity for motion toand fro along that pipe, between stops a, a'.

i imputation medseptembr 27, 1921..`

sectional elevation of through holes ax A packing o at the edge4noun"renti nenn; i

Serial No. 5035584.

of disk C gives an lair-tight frictional engagement with the innervwalls of cup B. p There is provided a suitable gland D whichscrewsalong` the fountain to compress avpacking-CZ, between the gland D andthe upper, inner end of thelfountain. Preferably inthe closed endv ofthecup B, Ii provide` a vent hole, normally-'closed by av screw plug, b,and at the open end of the cup, l provide gland b to compress a packingo between the cup and the fountain.

Preferably onthe` interiorsurface of cup B, I provide a stoporlstops e,soplaeed as to engage the disk when lthe cup has been moved outwardlytothe desiredlimit of its stroke.v l The upper end of pipe A fis openand is provided with a stop, a', between` which stop and another stop@fthe disk C may -move in a limited to and fro movement. VVhen the diskC is at the lower endof its move`` menaresting against stopa, itcoversand closes a holeor holes ax communicating with the interiorofpipeA (see Figurel). Vlhen disk C is at the upper --endof its movement ituncovers and opens 'holes a* thus 'forming` a passagefrom the fountainon one' side of disk C to the other., through `the disk (see` Figure 5The operation is as follows: i The parts being assembled as shown `inFigure l, to fill the pen thepen end of the fountain isjsubme'rged inink.A The operator holding the fountain `with one hand, 'grasps 'theouterlendof the cupBwith'the other and draws the cup outward.` rfhe.first effect of this action is to shift the disk C upward, on pipe A,by the frictional engagement of disk C and cup B, thus opening the holesaX in pipe A and a passage from one side of disk C to the other throughthe disk. The stop a, limits the upward movement ofdisk C and continuedmovement of cup B enlarges the space above disk C and induces a streamof air from below disk C to the interior of cup B, above disk C and pipeA. The consequent rariiieation of air in fountain 1 disturbstheatmospheric balance below disk C and causes ink to be forced into thefountain l and passage 5 and pipe A, by outside atmospheric pressure. l

' rlhe cup B is now pushed inward. The lirst edect `of this action is toshift the disk C downward on pipe A, by the frietional engagement ofdisk C and cup B, until disk C rests against stop a, and covers andcloses holes ax, thus closing the passage for air from rone side of diskC to the other side, which was opened upon the up stroke of cup B andsimultaneously diminishing the space above disk C, forcing the airthrough pipe A and passage 5, to the outer air, and expelling all theink that entered passage 5 or pipe A during the up stroke of cup B butin no wise affecting the ink drawn into the yfountain proper, since thepassage from the upper to the under side of disk C, above the ink in thefountain, was closed by the initial inward, air-compressing stroke ofcup B andfall air trapped in cup B is forced through the pipe A andpassage 5. The ink in the fountain proper continually gains at eachoutward stroke of the cup B as the fountain ink kis not subjected to anypressure 0n the inward stroke of cup B. All ink entering passage 5 orpipe A during an outward stroke of cup B is eX- vpelled on the nextinward stroke of cup B, so that ink never gains in passage 5and pipe Aand when the cup B has been operated a suflicient number of times, thefountain will be filled and pipe A` and passage 5, onthe final instrokeof cup B will be cleared of ink. The filling of the fountain with inkwill be indicated to the operator by the gradual decrease of ejected airbubbles at the immersed end of the fountain. When the bubbles begin todiminish the operation of the cup B should immediately cease.

I preferably form within cup B a slightly conical member 19X which, whenthe cup is in its inner position, fits and plugs the open, inner end ofpipe A. I

vI have shown and described above the preferred form and mode ofoperation of my device, in which the air is admitted on the up stroke ofthe cup, to the pipe and so passes through and above the disk. It isobvious, of course, that a separate aperture might be formed in thedisk, seating against a shoulder and being closed thereby on the downstroke of the cup and lifted from the shoulder and opened on the upstroke of the cup. Such a modification is shown in Figure 4t in whichthe shoulder is marked X, and the aperture in the disk C is marked 0X,the other parts being as in the other figures.

l claim:

l. In a fountain pen, the combination of a fountain; a cup slidablymounted in the open rear end of the fountain; a pipe longitudinallymounted within the fountain, open at its front end to the air and at itsrea-r end communicating with the interior of the cup; a disk mounted forlongitudinal move-ment upon the pipe at its rear end, within the cup andin frictional air tight engagement at its edges with the inner walls ofthe cup and having a passage therethrough, the disk moving to open thepas sage upon rearward movement of the cup and to close the passage uponforward movement of the cup.

2. In a fountain pen, the combination of a fountain; a cup slidablymounted in the rear end of the fountain; a pipe longitudinally mountedwithin the fountain, open at its front end to the air and at its rearend communicating with the interior of the cup and with the fountain; adisk mounted for longitudinal movement upon the pipe at its rear endwithin the cup and in frictional air tight engagement at its edges withthe inner walls of the cup, the disk moving to open the passage from thefountain to the interior of the pipe upon rearward Inovement of the cupand to close the passage upon forward movement of the cup.

Signed at Boston, Massachusetts, this 26th day of September, 1921.

OLIVER MITCHELL.

